docs(#2671): trim per-verb arg help (diff, list, lint, pr-merge)

Continue trimming clap arg help to user-relevant info: drop the
token-bounded-paging rationale (list --page), the why-it's-required
note (lint no-reviewer), the `Forgejo Do:`/`force_merge` API internals
(pr-merge), and tighten diff --full. pr-status was already clean.

hive-forge/src/verbs/diff.rs

@@ -23,10 +23,9 @@ use crate::client::{Client, index};
 pub struct Args {
     /// PR number.
     number: u64,
-    /// Print the unfiltered diff including autogenerated-file
-    /// hunks (`flake.lock`, `Cargo.lock`, etc.). Default is to
-    /// collapse those hunks to a placeholder so the human-authored
-    /// changes aren't drowned in lock churn.
+    /// Print the unfiltered diff. By default, autogenerated-file hunks
+    /// (`flake.lock`, `Cargo.lock`, …) are collapsed to a placeholder so
+    /// human-authored changes stay readable.
     #[arg(long)]
     full: bool,
 }